The Hematopathology Section of the Laboratory of Pathology, NCI, offers expert diagnostic services in the field of hematopathology. Dr. Stefania Pittaluga, Staff Clinician, and I handle diagnostic service responsibilities equally, each rotating as the staff on service 50% of the time. However, because of the challenging nature of the material we receive for review, and obligations related to specific clinical protocols and teaching conferences, our clinical obligations extend well beyond the designated on-service time. We provide assistance in the diagnosis and classification of reactive and neoplastic lymphoproliferative disorders, immunodeficiency states, and diverse hematological malignancies. We provide consultative and collaborative services to physicians in the National Cancer Institute, as well as to physicians studying patients with hematolymphoid disorders in other institutes, in particular NIAID, NHLBI, NHGRI, and NIAMSD. We serve as Associate Investigators on more than 35 clinical protocols being conducted in the NCI and other NIH institutes. These protocols frequently mandate specialized testing to illuminate biological markers relevant to the particular study. We receive more than 2000 cases in consultation each year. Because of the demands that the consultation service places on our time, we try to restrict consultations to difficult or challenging cases. Many cases are submitted by other academic institutions, based on diagnostic uncertainty, or because of differences of opinion among several institutions. We regularly refuse to accept consultations that we regard to be of a routine nature, and recommend that such cases be sent to routine reference laboratories. We frequently make novel observations based on this unique clinical practice, and a number of publications have emanated these experiences. Thus, I believe our clinical work enhances, rather than detracts, from our academic productivity.